JPH077331B2 - Control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device used in the periphery of a computer, and more specifically to an intervening means such as a printer buffer and a switch, or a peripheral device such as a printer connected via the intervening means. The present invention relates to a control device that issues a control command.

[0002]

2. Description of the Related Art In recent years, various intervening means such as a buffer and a switch, which are interposed between a computer and its peripherals and intervene in data exchange between them, have been widely used. For example, a printer buffer that is connected to a printer to buffer data, a printer switching device that enables one printer (or computer) to be used by a plurality of computers (or printers), and a large-capacity hard disk device. Examples thereof include a cache memory device interposed between and to enable high-speed data access, a modem for handling data transfer with a host computer, and the like.

Various settings exist in these intervening means, for example, switching of the connection state of the printer. Conventionally, such switching has been performed by directly operating the switch provided in the intervening means, but recently, in order to improve operability, a command is sent from the computer side to change the connection state with the printer. Various functions are added such as switching, erasing the contents of the buffer, outputting the contents of the buffer a plurality of times, and causing a printer to print a plurality of copies.

[0004]

However, in the configuration in which the command is transmitted from the computer, in order to coexist with other application software, it is necessary to develop resident software incorporated in the operating system (hereinafter referred to as OS). . In this case, software has to be developed for each OS and for each computer model on which the OS is installed, which poses a problem that enormous effort is required for the development.

In the case of resident software, it is normally started
It is performed by operating a key called a hot key (for example, control key + help key). Therefore, at least the part for detecting the operation of the hot key needs to be resident in a part of the memory, and in the type of application that occupies most of the memory, the resident software may not operate.

On the other hand, it is conceivable to provide a control device for issuing such a control command in an intervening means such as a printer buffer, but in order to issue the command, it is necessary to go to the intervening means side one by one, and the computer and the intervening means are required. If there is a gap between them, it becomes difficult to use. Further, if it is attempted to connect such a control device to the intervening means, there is a problem in that it is necessary to make a plurality of types of control devices according to the form of various intervening means, which requires considerable labor for development and manufacturing. It is not a realistic solution.

The control device of the present invention aims to solve these problems and output a command for control to the intervening means interposed between the computer and its peripheral equipment in a convenient manner. Therefore, the control device of the present invention has the following configuration.

[0008]

A control device of the present invention is connected to an intervening means such as a buffer and a switching device which is interposed between a computer and its peripheral equipment and which intervenes in exchanging data between them. A control device for controlling the intervening means, the instruction means being provided separately from the intervening means and the computer, for instructing issuance of a command for controlling the intervening means, and the computer and the intervening means. A command that is provided on a data transmission path and outputs the command to the intervening means when the command is instructed by the instructing means, interrupting or unrelated to the data exchange between the computer and the intervening means The gist is to have an output means.

[0009]

In the control device of the present invention, the issuing of a command for controlling the intervening means is instructed by the intervening means such as the buffer and the switch and the instruction means provided separately from the computer. At this time, the command output means provided on the data transmission path between the computer and the intervening means outputs a command for controlling the intervening means to the intervening means. When the command issuance is not instructed, the data transmission between the computer and its peripheral device is performed through the intervening means, and when the command issuance is instructed, the data transmission is interrupted. Command output is performed regardless of the transmission of data. Upon receiving the command, the intervening means performs preset control, such as control of changing the connection state and clearing the buffer.

Here, the command output means may be provided in the middle of a printing cable connected from the computer to an intervening means such as a printer. When data is transmitted using radio waves, light (visible light, infrared light, etc.), ultrasonic waves, etc., it may be configured as a remote controller that outputs a command to the intervening means by at least one of them. Good.

[0011]

Preferred embodiments of the present invention will be described below in order to further clarify the structure and operation of the present invention described above. FIG. 1 is a configuration diagram showing a connection relationship of a control device as an embodiment of the present invention. The control device 1 is connected to the printer connection port 5 of the computer 3 by a dedicated cable 7. The control device 1 uses the dedicated cable 7
Output connector 12 together with input connector 11 connected to
A printer buffer 15 having a printer switching function is connected to the output connector 12. Three printers 21, 22 and a plotter 24 are connected to the printer buffer 15.

Therefore, the control device 1 is interposed in the middle of the so-called Centronics printer signal line from the computer 3 to the printer or the like via the printer buffer 15. The Centronics specifications are specifications for a printer that transmits 8-bit parallel data while handshaking using a busy signal BUSY, and defines the role of each signal line and its electrical characteristics. It has become the de facto standard as a signal line for a printer in an ordinary personal computer or the like.

The configuration of the control device 1 will be described. Figure 2
FIG. 3 is a block diagram showing an internal configuration of the control device 1. As shown in the figure, the control device 1 is mainly composed of a one-chip microprocessor (MPU) 31 having a built-in ROM and RAM and having a plurality of bit input / output ports, and operates under the control of this MPU 31. Of the input / output ports of the MPU 31, predetermined 8 bits are used as the data output port D and are connected to one port of the bidirectional tristate buffer 33.

The other port of the tri-state buffer 33 is connected to the output connector 12 together with the port of the other tri-state buffer 35. The other port of the tri-state buffer 35 is connected to the input connector 11. Tri-state buffer 35
The signal passing through is the 8-bit print data P0 to P7.
And a busy signal BUSY from the printers 21, 22 and the like.

Printer 2 via printer buffer 15
The busy signal BUSY output from 1 or the like is a signal indicating that the printer 21 or the like cannot accept data during the high level, and is connected to the input port PA1 of the MPU 31 and the OR gate 38 in the control device 1. ing.
The other input terminal of the OR gate 38 is connected to the output port PB1 of the MPU 31, and its output is connected to the input connector 11 via the tristate buffer 35.

Two tri-state buffers 33 and 35
Are wired-OR connected, and an exclusive signal is input to each enable terminal. That is, the enable terminal of the tri-state buffer 33 is directly connected to the output port PB2 of the MPU 31, and the enable terminal of the tri-state buffer 35 is connected to the output port PB2 via the inverter 39.

The other input ports PC1 to PC7 of the MPU 31 are provided with command keys 41 to 45 and a setting key 46, which are provided on the front panel of the controller 1.
47 is connected. Command keys 41 to 45
Is to issue a control command to the printer buffer 15, and the setting keys 46 and 47 are to assign commands to the command keys 41 to 45. How to use these will be described later.

Next, regarding the processing performed by the MPU 31,
This will be described with reference to the flowchart of FIG. MPU31
3 repeatedly executes the command output processing routine shown in FIG. 3, and normally waits until the command keys 41 to 45 and the setting keys 46 and 47 are operated (step 100) while performing a key scan (step 100). 1
10).

When the command keys 41 to 45 are operated (step 110), the command preset corresponding to each command key 41 to 45 is read from the RAM (step 120), and then the busy mask is set. Processing is performed (step 130). Here, the process of setting the busy mask is a process of inverting the output port PB1 of the MPU 31 to a high level. When the output port PB1 is inverted to the high level, the OR gate 38
Is the busy signal BU from the printer buffer 15.
It goes high regardless of SY.

Next, the MPU 31 confirms the state of the input port PA1 and confirms that the busy signal BUSY is at low level (=
0) to determine whether the busy signal BUSY
Is high, it is determined that the printer 21 or the like is currently receiving data, and the process waits until the receiving operation is completed (step 140). By setting the output port PB1 to the high level (step 130), even if the busy signal BUSY from the printer buffer 15 is inverted from the high level to the low level, the busy signal BUSY output to the computer 3 is kept at the high level. . Therefore, when the computer 3 is outputting data, the printer 2
When the 1st class completes the input process of the data currently being received,
The computer 3 is made to wait for a while, and the command from the control device 1 can be received.

Busy signal B from printer buffer 15
When USY goes low (step 140),
The MPU 31 inverts the output of the output port PB2 to low level, and performs bus switching (step 150). As a result, the tri-state buffer 33 connected to the port D of the MPU 31 is enabled and the computer 3
Tristate buffer 35 provided on the line with the side
The input and output of are in the high impedance state.

The state of this switching is shown in FIG. MPU31
Before the output port PB2 is switched, the data transfer is performed between the computer 3 and the printer buffer 15 as shown in FIG.
When the output of is switched to the low level, the command can be transferred from the MPU 31 to the printer buffer 15 as shown in (B).

Therefore, the MPU 31 outputs the command after switching the buses (step 160).
The command output here is a command read from the RAM in accordance with the operated command key 41 to 45. The command is composed of a special character string not included in normal data, for example, a character string starting with “@BF” and the like, and a predetermined command character string following the character string. These commands are not only received by the printer buffer 15 to switch their functions, but also pass through the printer buffer 15 and reach the printer 21 or the like in some cases. ) Is switched. Note that, along with the output of the command, until the input of this command is completed, the busy signal BU
SY is inverted to high level.

Subsequently, the MPU 31 has the input port PA1.
The state is checked, and it waits until the busy signal BUSY is inverted to the low level (step 170). After the busy signal BUSY becomes the low level, the busy mask is reset and the bus is switched (step 180). The busy mask is reset by dropping the output port PB1 to low level, and the bus switching is performed by inverting the output port PB2 to high level.

After the above processing, the process goes to "END" to end this processing routine. When it is determined that the key input is the setting key (step 110), command setting processing is performed (step 200), the process ends in "END" and the present routine ends.

In this embodiment, the command keys 41 to 4 are used.
Five commands are set in each of the five commands, as shown in FIG. Command A set in command key 41
Is a control command for the printer buffer 15 and is a command for switching the printers 21, 22 or the plotter 24. Each time the command key 41 is operated, a switching command is output, and the devices of the computer 3 that output data are switched in order. Command key 42
The command B set to is a command for clearing the contents of the printer buffer 15.

Command C set in command key 43
Is a command for temporarily stopping the output of data from the printer buffer 15 to the printer 21 or the like, and each time the command key 43 is operated, the printer 21 or the like repeatedly suspends and restarts the output. Also, command key 4
The command D set to 4 is a control command for the printer sent to the printer 21 and the like, and switches the emulation mode of the printer. Each time the command key 44 is operated, the printer 21 or the like sequentially switches its emulation mode. The command E set in the command key 45 is also a control command for the printer that is sent to the printer 21 and the like, and switches the printing speed of the printer between high speed and normal. Each time the command key 45 is operated, the printing speed of the connected printer 21 or the like is switched between high speed and normal.

The process of setting commands in the command keys 41 to 45 (step 200 in FIG. 3) is performed as follows. The control device 1 stores most of the commands in the built-in ROM in advance, but it is also possible to download the commands from the computer 3 to the RAM. When the setting key 46 is operated once, the control device 1 enters the command storage mode. When the setting key 47 is operated in this state, the commands stored in the ROM are sequentially called. Refer to the manual, etc., and set the preset number of times 47
When the desired command is called, the setting key 46 is operated. As a result, the desired command is stored in the RAM, and when the command key 41 to 45 is operated next, the commands A to E corresponding to the command key 41 to 45 are transmitted to the printer buffer 15 or the printer buffer by the processing described above. It is output to the printer 21 or the like via 15.

Since the control device 1 of the present embodiment described above can be installed near the computer 3, the printer buffer 15 is moved away from the computer 3 to switch the states of the printer buffer 15 and the printer 21. There is no need to go near the printer 21 or the like. Moreover, since the control device 1 is installed in the signal line of the Centronics standard, which is the de facto standard of the signal line for the printer,
It does not depend on the model of the computer 3, the printer buffer 15 or the printer 21. Further, it is not necessary to incorporate software for outputting a command into the OS or the like of the computer 3, and also in this respect, the model or the OS of the computer 3
Does not depend on the type of. As a result, the labor of development is greatly reduced, and since it is not necessary to prepare the control device 1 according to the type of the computer 3 or the like, the management of the production process and the stock management become easy. Further, since it is not necessary to incorporate the resident software of the computer 3, even if the application being used in the computer 3 occupies most of the memory, it is possible to switch by the command of the printer buffer 15 or the like.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment. For example, the control device of the present invention is connected to a cache memory connected to a computer. Configuration, RS-232
A configuration in which the control device of the present invention is connected between a modem or the like interposed in a communication line such as C, and control commands can be issued to an intervening means for wirelessly exchanging data without interrupting data transmission. Needless to say, the present invention can be implemented in various modes without departing from the scope of the present invention, such as the configuration for transmitting.

[0031]

As described above in detail with reference to the embodiments,
In the control device of the present invention, it is possible to output a command to an intervening means such as a printer buffer without leaving the computer side, and it is not necessary to carry out development depending on the computer model or OS such as resident software. It has an excellent effect. Also, a computer and its OS
Alternatively, there is an advantage that it is possible to flexibly deal with the types of peripheral devices.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a connection relationship of a control device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a control device 1.

FIG. 3 is a flowchart showing a command output processing routine in the control device 1.

FIG. 4 is an explanatory diagram showing a transfer state of data and commands in the control device 1.

FIG. 5 is an explanatory diagram showing an example of command keys 41 to 45.

[Explanation of symbols]

 1 Control Device 3 Computer 15 Printer Buffer 21, 22 Printer 24 Plotter 31 MPU 41 to 45 Command Key 46, 47 Setting Key

Claims (2)

[Claims] 1. A control device which is interposed between a computer and its peripheral equipment and which is connected to an intervening means such as a buffer and a switching device for intervening in data exchange between the computer and the peripheral equipment and which controls the intervening means. The instruction means is provided separately from the intervening means and the computer, and is provided in an instruction means for instructing issuance of a command for controlling the intervening means, and in the data transmission path between the computer and the intervening means. A command output means for interrupting the transmission of data between the computer and the intervening means or for outputting the command to the intervening means irrespective of the transmission when the command is issued. apparatus. 2. The control device according to claim 1, wherein the command output means is provided in the middle of a printing cable connecting the computer and the intervening means involved in printing.